The most prominent immune checkpoint blocking strategies, such as targeting cytotoxic T lymphocyte‐associated protein 4 (CTLA‐4) and blocking the interaction between programmed cell death 1 (PD‐1) and PD ligand 1 (PD‐L1), are able to enlist and strengthen the immune system to attack cancer cells and have achieved clinical success in several cancer types, even in metastatic and chemoresistant cancer.13, 14. This evidence concerns the gene CTLA4 and cancer.